1. Field
Embodiments of the present disclosure relate to a DC power supply apparatus configured to correct an input polarity of a DC power.
2. Description of the Related Art
A DC power supply apparatus originated from a digital apparatus and an Internet data center (IDC), due to an increasing efficiency as a result of a declining power conversion process, an easy link with an uninterrupted power supply apparatus, and an efficient link with new regeneration energy and a charging system for electric vehicles, is being considered for expansion for household use.
As such, the DC power supply apparatus having a direct current as input power is required to be exactly connected with a positive (+) end and a negative (−) end at an input of the commercial power supply.
If the polarity of the DC power supply apparatus connected to the input of the commercial power supply is changed, not only the load may fail to operate, but also the DC power supply apparatus may burn out.
That is, since most electronic devices are equipped with an electrolytic capacitor at the input of the power supply apparatus, and such electrolytic capacitor is at risk of damage or explosion when the power having a reverse polarity is applied to the electrolytic capacity, it is imperative to determine the exact input polarity particularly when the supply of the DC power is introduced for household use.
Conventionally, by disposing a diode rectifier, which is provided with the total of four diodes coupled together in the form of a bridge, between the input of the commercial power supply and the power supply apparatus of the load, the voltage having the bipolarity is applied to the electrolytic capacitor, that is the DC link, thereby preventing the electrolytic capacitor and the load from being influenced by the polarity of the commercial power supply.
That is, the diode rectifier, when applied to the AC power supply apparatus, allows the bipolarity to be applied to the electrolytic capacitor even in a case when the AC voltage is alternately applied, and the diode rectifiers applied to the DC power supply apparatus may correct the input polarity with respect to the inputs of both the positive (+) polarity and the negative (−) polarity.
In a case when the input polarity is to be corrected by using the diode rectifier, however, since two diodes in the diode rectifier are conducted at all times, a loss caused by a drop of the voltage of the diode and a loss caused by an internal resistance of the diode occur.
That is, the diode rectifier having 600V of a rated voltage, which may generally be used at the DC power supply of 380V, normally shows a voltage drop in a range between 1.0V and 1.3V.
As an example, in a case when the internal resistance of the diode is not considered while assuming that the voltage drop occurs at about 1.1V, the maximum loss of power that may occur at a drum type washing machine having a capacity of 3.65 kW is about 42.96 W.
As such, in a case when correcting a polarity using the diode rectifier, the overall efficiency of an electronic device may be reduced. In particular, the correcting of a polarity using the diode rectifier may cause inefficient power consumption of a battery of a mobile digital device, and furthermore, may decrease the overall performance of the mobile digital device.